Diode side pumped lasers are well known in the art, see U.S. Pat. Nos. 5,778,020 and 5,774,488. For producing high power output from side-pumped solid state lasers, a number of diode bars have been tightly packed together to pump Nd:YAG lasing rod from symmetrically oriented multi-angles to produce high average power. When the laser crystal is not as durable as Nd:YAG, such as Nd:YLF, high pumping intensity along with high laser peak intensity and high average power often results in damage of the laser crystals. For example, current limitation for diode side pumped Q-switched pulsed Nd:YLF laser producing second harmonic wavelength beam is about 20 mJ/pulse at 1 kHz repetition rate. A higher pulse energy from Nd:YLF laser at fundamental or second harmonic wavelength at kHz repetition rates is desirable in many applications such as pumping short pulse amplifiers, dye lasers, high speed particle image velocimetry, laser welding and the like.